The present invention generally relates to an apparatus and method for forming reclosable storage containers such as flexible pouches having an easily openable and readily reclosable access opening that has mating flexible closure strips with complementary interlocking profiles. In its typical form, the invention includes features for filling and sealing as well as for forming the storage containers. The invention is especially suitable for providing reclosable storage containers in connection with packaging food products within a container assembly including a flexible pouch that is within a carton formed from a foldable sheet material, this type of container assembly being generally known as a bag-in-box packaging assembly.
Packaging of products for retail sale and consumption has developed gradually over the years in order to enhance the ease with which the consumer can open the packaging in order to gain access thereto for use or consumption of the food product therewithin. It is necessary for such packaging, before it is first opened by the consumer, to serve as a long-term storage container while the package is in warehouse storage and is on the retail shelf. Another desirable attribute of such packaging is that it provide an assembly that closes securely and in as air-tight a manner as possible in order to maintain the freshness of the food product remaining within the package. Food products that are typically thus packaged and stored within a box or carton having an internal liner or pouch include dry cereal products, especially such cereal products that require hermetic sealing from atmospheric air and humidity conditions during warehouse and retail shelf storage.
Heretofore, sealing of these types of products in these types of packages has been adequately achieved for warehouse and retail shelf storage prior to initial opening by the consumer. However, substantial difficulties have been encountered in incorporating an access opening into this type of packaging such that it will reclose or rescal in a secure and substantially air-tight manner so as to avoid premature deterioration of the food product within the packaging after its original seal that was formed at the packaging plant has been broken by the consumer. Various approaches have been taken in this regard. With most food products, including breakfast cereal products, such approaches often center upon providing a pouch opening that permits the consumer to fold over the top end of the pouch and reclose the top end or a portion of the top end of the carton or box by a suitable assembly including various tabs, slits, folds, tear paths and the like. Such a reclosing approach is usually adequate to prevent unintentional spillage or dust contamination of the product, but same is less than satisfactory for maintaining the freshness of the product and preventing its deterioration due to the excessive passage of air through the reclosed access openings.
Another disadvantage of a typical previously utilized closure arrangement for a bag or pouch of the type that is suitable for use within a box or carton assembly is the difficulty in opening the access assembly of the bag or pouch. Often, such assemblies require a tearing of the top sealing portion of the bag or pouch which, once torn, is permanently damaged and cannot easily be manipulated for adequate closure. Other sealing arrangements are intended to involve the pulling apart or delamination of opposing panels of pouch material which is intended to avoid such tearing. Usually, this approach is not entirely satisfactory because the seal to be pulled apart must be adequate to permit warehouse or retail shelf storage for many months, which requires adherence characteristics that are typically too tenacious to permit easy opening or breaking of that adherence seal when the package is to be opened by the consumer. This situation typically results in tearing of the film material sheets by the consumer which leads to the resultant inability to adequately reclose the pouch and container.
The present invention recognizes that an important step in overcoming these shortcomings and deficiencies is attained by forming, filling and sealing pouches having a reclosable closure assembly that includes mating flexible closure strips. When such mating flexible closure strips are handled, difficulties arise because of the bulkiness associated with mating flexible closure strips. A particular problem that arises in this regard is the development of excessive undesirable creases or fold-overs during formation of the pouch. To a great extent, the present invention substantially limits or avoids these deformities by controlling movement of the mated flexible closure strips while the pouch forming material supporting the strips is being oriented for completion of its formation into filled and sealed pouches suitable for bag-in-box container assemblies.
Achieving such control according to the apparatus and method of this invention includes using a web spreading assembly having a structure for quiding previously mated longitudinal strips that are located generally along a longitudinal edge of a flowing web of flexible sheet material. The flowing web is initially wrapped generally around a fill tube structure and the strips are mated to form a generally circular joined web. The spreading assembly manipulates the joined web as it flows in order to gradually transform same from a generally circular cross-section to a spread or flattened, generally elliptical cross-section. Such spreading can be facilitated by providing a fill tube assembly that has a tapering outside surface which permits the desired change of cross-sectional shape to begin to occur at a location that is more upstream than would otherwise be possible.
The apparatus and method according to the present invention which embody these features has the ability to form, fill and seal pouches that provide warehouse and shelf storage attributes which are adequate for many food products while forming pouches that possess an access opening seal which is readily openable without tearing the pouch material. Furthermore, once such access opening is initially opened by the consumer, it is readily reclosable in a secure and air passage inhibiting manner.
It is accordingly a general object of the present invention ot provide an imporved apparatus and method for forming reclosable storage containers.
Another object of this invention is to provide an improved apparatus and method for forming reclosable storage pouches from a web of flexible sheet material having matable and flexible closure strips while controlling or avoiding the formation of wrinkles or folds along sealing areas of the pouches thus formed.
Another object of the present invention is to provide an improved apparatus and method for forming reclosable storage containers having an access arrangement which, while being easy to open, is a tightly sealed assembly that permits detection of tampering or pilfering activities before purchase or use by the consumer.
Another object of this invention is to provide an improved form-fill-seal apparatus and method that manipulate and form film material sheets into pouches, fill those pouches with food material product, and seal the pouches in a hermetic manner and is a condition suitable for insertion within boxes or cartons that are closely sized to the bag or pouch.
These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.